The invention relates to digital tape drive storage devices, and in particular, to a half-inch tape drive having a half high form factor.
Tape drives have been widely employed in industry for over thirty years due to their ability to store large amounts of data on a relatively small inexpensive removable format. The data is stored on tape drives utilizing a variety of designs, but in all cases, magnetic tape media is wound between a pair of tape reels as data is transferred to or from the tape media. The standard tape media employed in many applications is a one half-inch wide tape media housed in a tape cartridge measuring at or near 1 inch in height. Presently, all tape drives that utilize half-inch tape media are constructed in a full height five and a quarter (5.25) inch or larger form factor as defined by: EIA specification No. 3877-A xe2x80x9cSmall Form Factor 133.35 mm (5.25) Disk Drives.xe2x80x9d One example of a full height five and a quarter (5.25) form factor for tape drives includes a width dimension xe2x80x9cWxe2x80x9d of 5.75 inches a depth dimension xe2x80x9cDxe2x80x9d of 8.1 inches and a height dimension xe2x80x9cHxe2x80x9d of 3.2 inches. Therefore, half-inch tape drives occupy two drive bays when installed in a conventional computer housing.
In the art of data storage, the physical space required to store data is an important concern. Thus, it is desirable to have a half-inch tape drive that is constructed with a half height form factor that can be installed in a single drive bay in a conventional computer housing. The half height form factor, also defined in EIA specification No. 3877-A xe2x80x9cSmall Form Factor 133.35 mm (5.25) Disk Drivesxe2x80x9d includes a maximum height of 1.634 inches. Unfortunately, in addition to the fact that half-inch tape cartridges are approximately 1 inch by themselves, several other design requirements make achieving a half-height form factor in a half-inch tape drive extremely difficult.
FIG. 1 illustrates one example of a typical half-inch tape drive 100. The tape drive 100 is a DLT tape drive that employs a single reel DLT tape cartridge design. This design includes a supply reel located within a tape cartridge (not shown) and a takeup reel 101 located within the tape drive 100. Referring to FIG. 2, the tape media on the tape cartridge is terminated at one end by a tape cartridge leader 201. The tape cartridge leader 201 is a strong flexible plastic strip containing an ovular aperture 202 on its distal end. A takeup leader 203, that connects to the takeup reel 101, is a similar plastic strip that includes a stem 204 and tab 205 designed to buckle with the ovular aperture 202 on the tape cartridge leader 201 to form buckle 200. The tape cartridge leader 201 also includes a section 206 that is slightly wider than the rest of the tape cartridge leader 201 and the takeup leader 203. The wider section 206 prevents the tape cartridge leader 201 from being pulled into the tape cartridge after the tape cartridge leader 201 and takeup leader 203 are disconnected for ejection of the tape cartridge.
Upon loading the tape cartridge into the tape drive 100, the takeup leader 203 and tape cartridge leader 201 are buckled, and the tape media is wound to a start point or read position. To accommodate the slightly wider section 206 during winding of the tape cartridge leader 201 and the takeup leader 203 around the takeup reel 101, the takeup reel 101 includes a wider stepped area 102 formed in the top and in the bottom flanges, 112 and 113, of the takeup reel 101. Unfortunately, the stepped area 102 adds approximately a quarter of an inch to the height of the takeup reel 101 and the overall height of the tape drive 100.
Another design requirement in half-inch tape drives is the physical size of the tape deck 109. The tape deck 109 functions as a supporting surface for the various mechanical and electrical components, such as the takeup reel 101, tape guides 103-106, the read/write head 107 and the printed circuit board (xe2x80x9cPCxe2x80x9d) 108 mounted on the underside of the tape deck 109. To maintain an accurate alignment of the takeup reel 101, tape guides 103-106 and the read/write head 107, during operation of the tape drive 100 requires a rigid tape deck 109. To achieve the necessary rigidity in the tape deck 109, typical DLT tape drive decks are approximately one (1) inch in height. Additionally, the PC board 108 is mounted on the underside of the tape deck 109 further adding to the overall height of the tape deck 109 and the tape drive 100.
Finally, another design requirement in half-inch tape drives is the loading mechanism that engages the tape cartridge drive mechanism 110 through a toothed coupling. The loading mechanism comprises a vertically mounted load motor 111 coupled to a spur gear train (not shown) that engages the cartridge drive mechanism 110. Unfortunately, the load motor 111 is mounted vertically in order to engage the gear train and move the cartridge drive mechanism 110 vertically up and down to engage and disengage the tape cartridge reel when a tape cartridge is inserted into the tape drive 100. The vertically mounted load motor 111 again adds to the overall height of the tape drive 100.
The present invention overcomes the problems outlined above and advances the art by providing a half-inch tape drive that is implemented in a half height form factor. A first advantage of the present half-inch tape drive is that it accommodates conventional half-inch tape cartridges. It can be appreciated that not modifying the tape cartridge format represents a significant advantage to consumers whose data is currently stored on half-inch tape cartridges. A second advantage of the present half-inch tape drive is that the half height form factor permits installation of this tape drive in a single drive bay in a conventional computer housing. A third advantage of the present half-inch tape drive is improved manufacturability resulting from the reduction in material and design improvements. Additionally, one skilled in the art will appreciate numerous other advantages of the half-height form factor, such as doubling the storage capacity in a single computer by the accommodation of twice as many tape drives and the additional flexibility added to data storage design.
The present half-inch tape drive comprises a novel takeup reel, tape deck, PC board packaging, loading mechanism, and housing. The takeup reel comprises a takeup reel hub connected between a pair of segmented flanges that define first and second tape containment sections. The tape deck is approximately half the height of a conventional tape deck and includes reinforcing ribs that provide structural rigidity to maintain alignment of the moving components of the tape drive during operation. The tape deck also includes a plurality of guiding ribs that cooperate with the takeup reel to vertically align the tape media in the tape path during power interruptions. The loading mechanism comprises a horizontally mounted load motor that connects to a simplified gear train. A worm gear provides the connection between the load motor and the gear train and permits the horizontal mounting of the load motor. The PC board packaging comprises a first PC board section mounted in a first location, a second PC board section mounted in a second location and a third PC board section mounted in a third location on the tape drive. The separate PC board sections and mounting locations maximize spatial efficiencies and reduce the overall height of the tape drive. The first, second, and third PC board sections are electrically connected by flex cables that further improve the spatial utilization in the tape drive. The tape drive housing provides a protective exterior for the present tape drive and provides the structure for mounting the present tape drive in a single drive bay of a computer housing.